Harold Aus Petterson - Chicago to Los Angeles 1900

I am looking for info about my gfather Harold Petterson and his parents/siblings. Harold, b. 1880 in Chicago, IL, moved to Los Angeles (Compton, CA) about 1900. He married Callie Harshman in Compton about 1908. His parents are listed as being born in Norway. I have no info about them or any siblings. Thanks for any help. Nancy Casey